In the study of binge drinking mentioned in Exercise 10.3, the percent who said they had engaged in unplanned sexual activities because of drinking alcohol was 30.7% in 1999 and 23.0% in 2009. Is this change statistically significant at the 0.05 significance level?
a. Specify assumptions, notation, and hypotheses for a two-sided test.
b. Show how to find the pooled estimate of the proportion to use in a test. (You need the count in each year rather than the proportion. In 1999, note this is (0.307)334 = 103.) Interpret this estimate.
c. Find the standard error for the difference used in the test. Interpret it.
d. Find the test statistic and P-value. Make a decision using a significance level of 0.05.